Use of an array of polymeric sensors of varying thickness for detecting analytes in fluids

• US 6,610,367 B2
• Filed: 07/20/2001
• Issued: 08/26/2003
• Est. Priority Date: 11/16/1998
• Status: Expired due to Term

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Freund, Michael, Matzger, Adam J., Severin, Erik J., Lewis, Nathan S.
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): Handy, Dwayne K
• Application Number:
  US09/910,242
• Publication Number:
  US 20020197390A1
• Time in Patent Office: 767 Days
• Field of Search: 422/68.1, 422/82.01, 422/82.02, 422/82.03, 422/98, 436/149, 436/150, 204/406, 204/415, 204/418, 427/2.1, 427/2.11, 427/421, 427/427, 427/429
• US Class Current: 427/58
• CPC Class Codes: G01N 15/0826 and measuring fluid flow rate, i.e. permeation rate or pressure change
• CPC Class Codes: G01N 2291/0217 Smoke, combustion gases
• CPC Class Codes: G01N 2291/0256 Adsorption, desorption, surface mass change, e.g. on biosensors
• CPC Class Codes: G01N 2291/02863 Electric or magnetic parameters
• CPC Class Codes: G01N 2291/0423 Surface waves, e.g. Rayleigh waves, Love waves
• CPC Class Codes: G01N 2291/0426 Bulk waves, e.g. quartz crystal microbalance, torsional waves
• CPC Class Codes: G01N 27/126 comprising organic polymers
• CPC Class Codes: G01N 29/022 Fluid sensors based on microsensors, e.g. quartz crystal-microbalance [QCM], surface acoustic wave [SAW] devices, tuning forks, cantilevers, flexural plate wave [FPW] devices microdevices per se B81B
• CPC Class Codes: G01N 29/449 Statistical methods not provided for in G01N29/4409, e.g. averaging, smoothing and interpolation
• CPC Class Codes: G01N 33/0031 comprising two or more sensors, e.g. a sensor array

Abstract

Chemical sensors for detecting the activity of a molecule or analyte of interest is provided. The chemical sensors comprise and array or plurality of sensors that are capable of interacting with a molecule of interest, wherein the interaction provides a response fingerprint. The fingerprint can be associated with a library of similar molecules of interest to determine the molecule'"'"'s activity and diffusion coefficient.

Claims

1. A method of forming an electrically conductive polymer sensor, said method comprising,

providing a solution or suspension comprising at least a first conductive material and at least a second conductive material compositionally different than the first material in a solvent;

providing a substrate comprising at least a first conductive lead and at least a second conductive lead; and

applying the solution or suspension to the substrate using a spray apparatus such that the solution or suspension creates a region between the first conductive lead and the second conductive lead, wherein the region comprises the first conductive material and the second conductive material compositionally different than the first material.

2. The method of claim 1, wherein the second material is a conductive organic material.

3. The method of claim 2, wherein the conductive organic material is selected from the group consisting of polyanilines, an emeraldine salt of polyaniline, polypyrroles, polythiophenes, polyEDOTs, and derivatives thereof.

4. The method of claim 1, wherein the first conductive material is carbon black.

5. The method of claim 1, wherein the solution or suspension is continuously stirred prior to application.

6. The method of claim 1, wherein the spray apparatus is an airbrush.

7. The method of claim 6, wherein the solution or suspension is applied using an airbrush fitted with a nozzle capable of applying a stream of solution or suspension in a desired geometry.

8. A method of forming an electrically conductive polymer sensor, said method comprising,

providing a solution or suspension comprising at least a first conductive material and at least a second material compositionally different than the first material in a solvent;

providing a substrate comprising at least a first conductive lead and at least a second conductive lead; and

applying the solution or suspension to the substrate using a spray apparatus comprising an airbrush fitted with a nozzle for applying the solution or suspension in a desired geometry such that the solution or suspension creates a region between the first conductive lead and the second conductive lead, wherein the region comprises the first conductive material and the second material compositionally different than the first material.

11. The method of claim 8, wherein the coating is accomplished by spraying the at least one substrate with an air-brush.

9. A method of making a sensor array comprising;

coating at least one substrate comprising at least two conductive leads with a suspension comprising a first conductive material and a first material compositionally different than the first conductive material to form an at least one first sensor having a film comprising regions of a first conductive material and regions of a first material compositionally different than the first conductive material between the conductive leads; and

coating the at least one substrate with a suspension comprising a second conductive material and a second material compositionally different than the second conductive material to form an at least one second sensor having a film comprising regions of a second conductive material and regions of a second material compositionally different than the second conductive material between the conductive leads.

10. The method of claim 9, wherein the coating of the substrate is accomplished by a process selected from the group consisting of solution casting, suspension casting, sparring with an air-brush, and mechanical mixing.

12. The method of claim 9, wherein the first material compositionally different from the first conductive material and the second material compositionally different from the second conductive material are selected from the group consisting of a conductive organic material, a semi-conductive material, and a non-conductive material.

13. The method of claim 9, wherein the first material compositionally different than the first conductive material and the second material compositionally different than the second conductive material are the same.

14. The method of claim 9, wherein the first conductive material and the second conductive material are selected from the group consisting of an inorganic conductor and carbon black.

15. The method of claim 9, wherein the first conductive material and the second conductive material are selected from the group consisting of Ag, Au, Cu, Pt, carbon black, and AuCu.

16. The method of claim 9, wherein the first conductive material and the second conductive material are compositionally the same.

17. The method of claim 13, wherein the first conductive material and the second conductive material are compositionally the same.

18. The method of claim 9, wherein the film of the at least one first sensor and the film of the at least one second sensor comprise a different thickness.

19. A method of making a sensor array comprising:

simultaneously coating a plurality of substrates, each substrate comprising at least two conductive leads, using a technique selected from the group consisting of a spraying technique, a technique comprising spraying with an air-brush, and a mechanical mixing technique, with a suspension comprising a first conductive material and a second material compositionally different than the first material to form a plurality of sensors, each of the sensors constructed to provide a first response when contacted with a first chemical analyte, and a second different response when contacted with a second different chemical analyte.

20. The method of claim 19, wherein the coating is accomplished-by spraying with an air-brush.

21. The method of claim 19, wherein the second material is selected from the group consisting of a conductive organic material, a semi-conductive material, and a non-conductive material.

22. The method of claim 19, wherein the first conductive material is selected from the group consisting of an inorganic conductor and a carbon black.

23. The method of claim 19, wherein the first conductive material is selected from the group consisting of Ag, Au, Cu, Pt, carbon black, and AuCu.

24. The method of claim 19, wherein the coating of at least one substrate of the plurality of substrates results in a film on a sensor being thicker than at least one other sensor in the sensor array.

25. A method of making a sensor array comprising:

spraying a plurality of substrates, each substrate comprising at least two conductive leads, with a suspension comprising a first conductive material and a second material compositionally different than the first material using a spray apparatus comprising an airbrush fitted with a nozzle for applying the solution or suspension in a desired geometry such that the suspension forms a film comprising regions of a first conductive material and regions of a second material compositionally different than the first material between the conductive leads on each substrate.

26. A method of making a plurality of sensors comprising:

spraying a substrate comprising at least two conductive leads in a first area with a composition comprising at least one material to form an at least one first sensor; and

spraying the substrate in an at least one second area with the composition to form an at least one second sensor;

whereby the at least one first sensor and-at least one second sensor comprise the same composition, wherein each of the sensors provides a first response when contacted with a first chemical analyte, and a second different response when contacted with a second different chemical analyte.

27. The method of claim 26, wherein the at least one first sensor and at least one second sensor are of a different thickness.

28. The method of claim 26, wherein the composition comprises a first conductive material and a second material compositionally different than the first conductive material.

29. The method of claim 26, wherein the composition is in the form of a sprayable solution or suspension.

30. A method of making a plurality of sensors comprising:

coating a plurality of substrates, each substrate comprising at least two conductive leads, using a technique selected from the group consisting of a spraying technique, an air-brush technique, and a mechanical mixing technique, with a suspension comprising a first conductive material and a second material compositionally different than the first material to form a plurality of sensors, each of the sensors constructed to provide a first response when contacted with a first chemical analyte, and a second different response when contacted with a second different chemical analyte.

31. The method of claim 30, wherein. the at least two conductive leads are attached to the substrate either before or after the coating of the substrate with the first material and second material.

32. The method of claim 30, wherein the at least one sensor of the plurality of sensors comprises a different thickness than at least one other sensor in the plurality of sensors.

33. The method of claim 30, wherein the first material is selected from an inorganic conductor and a carbon black.

34. The method of claim 33, wherein the inorganic conductor is selected from the group consisting of Ag, Au, Cu, Pt, and AuCu.

35. The method of claim 33, wherein the first material is carbon black.

36. The method of claim 30, wherein the second material is selected from the group consisting of a conductive organic material, a semi-conductive material, and a non-conductive material.

37. The method of claim 36, wherein the conductive organic material is selected from the group consisting of polyanilines, an emeraldine salt of polyanilines, polypyrroles, polythiophenes, polyEDOTS, and derivatives thereof.

38. The method of claim 30, wherein the coating of suspension is applied to the substrate by a spray of suspension.

39. The method of claim 30, wherein the coating is accomplished by spraying the suspension on the substrate with an airbrush.

40. The method of claim 39, wherein an airbrush is fitted with a nozzle for applying the suspension in a desired geometry.

41. A method of making a plurality of sensors comprising:

spraying a plurality of substrates, each comprising at least two conductive leads, with a composition comprising at least one material to form a film between the at least two conductive leads thereby forming a plurality of sensors;

whereby the plurality of sensors comprise the same film composition, wherein each of the sensors provides a first response when contacted with a first chemical analyte, and a second different response when contacted with a second different chemical analyte, and wherein the film comprises at least a first conductive material and a second material compositionally different than the first conductive material.

42. The method of claim 41, wherein the first conductive material is selected from the.group consisting of Ag, Au, Cu, Pt, carbon black, and AuCu, and the second material compositionally different than the first material is selected from the group consisting of a non-conductive material, a semi-conductive material, a conductive organic material, wherein the conductive organic material is selected from the group consisting of a polyaniline, an emeraldine salt of polyaniline, a polypyrrole, a polythiophene, and a polyEDOT.

43. The method of claim 41, wherein the spraying is performed with a spray apparatus.

44. The method of claim 43, wherein the spray apparatus comprises a nozzle for spraying in a desired geometry.

45. The method of claim 44, wherein the spray apparatus is an airbrush.